Re: nvram to protect fs during power loss?

[Spam <spam@tnonline.net>]

  Yes, I know that good hardware already do use battery backups and
  similar. But I was talking about normal consumer hardware; desktops,
  laptops, etc.

  I do not know how the internals of reiser4 works, but one of the
  problems said to be that it cannot be certain about the order and
  integrity of the data if a power failure occur. But if reiser4
  stored some kind of index number, key etc, on regular intervals then
  that could certainly help in recovering the filesystem to a working
  state.

  As it is now you can end up with a severely broken filesystem that
  doesn't even mount if you have a power failure. IMO a filesystem
  should do its best to protect the data on it. I thought that perhaps
  using NVRAM could aid in the recovery after the powerloss, instead
  of tossing a user "bad error, use --build-sb to fix" during next
  boot.

  ~S

  

> On Fri, Dec 31, 2004 at 12:40:08AM +0100, Spam wrote:
>> 
>>   There have been some discussions about recovery abilities during
>>   power loss if write cache is enabled. Some recovery tool I saw once
>>   used NVRAM to store progress info so that if you had a power loss it
>>   would be able to resume.

> Typically specialized hardware, typically used for NFS (which is stateless) doing
> "caching" of the writes to enhance performance.

>>   Perhaps it would be possible for Reiser4 to store some info, like
>>   time indexes etc in NVRAMwhen it send sync commands to the disk.
>>   This way it might be possible to avoid corruptions by simply
>>   verifying (fsck) the data stored after that time index etc?

> The way the journals/logs does??
´

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